// 清楚默认样式
h1,h2,h3,h4,h5,ul,li,p {
  margin: 0;
  padding: 0;
}
ul,li {
  list-style:none
}
// flex布局 x轴 两端对齐
.flex_x_b {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
// flex布局 y轴 两端对齐
.flex_y_b {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

//  圆角
.bor_rd_4 {
  border-radius: 4px;
}


// 下边框线
.border_w2_b {
  border-bottom: 2px solid #f7f7f7;
}